1. Field of the Invention
The present invention relates to a method of operating an internal combustion engine, especially for or in a motor vehicle, in which air is fed to a combustion chamber via a regulating valve arranged in an intake pipe and the mass flow through the regulating valve is determined and in which exhaust gas is feedback into the intake pipe through an exhaust feedback valve arranged in an exhaust gas feedback line, and the mass flow through this latter valve is determined. Furthermore the present invention relates to an internal combustion engine, especially for a motor vehicle, comprising a regulating valve arranged in an intake pipe, through which air is supplied to a combustion chamber, an exhaust feedback valve arranged in an exhaust feedback line, by means of which exhaust gas is fed into the intake pipe and a control unit, with which the mass flow through the regulating valve and the mass flow through the exhaust feedback valve in the exhaust gas feedback line are determined and adjusted.
2. Prior Art
The requirements for modern internal combustion engines in regard to reduction of fuel consumption and the pollutants and/or exhaust gases emitted are ever more stringent and/or higher. For these reasons the metering of fuel into the combustion chamber of the internal combustion engine must be further improved, particularly the metering of fuel mass must be made more accurate. For this purpose in the known internal combustion engine the mass flow of the air supplied to the combustion chamber through the regulating valve or flap is measured with the help of an air mass sensor, e.g. a so-called HFM sensor. The mass flow measured in this way is then used to calculate the required associated mass of fuel to be injected, which is required in order to attain the predetermined vehicle state desired by the operator of the motor vehicle, for example an acceleration of the motor vehicle.
Especially for further reduction of the exhaust pollutants in modern internal combustion engines a so-called exhaust gas feedback is provided, in which the exhaust gas output from the internal combustion chamber is fed back through a valve to the intake pipe and thus to the combustion chamber. The mass flow through this valve can be set, for example by means of a signal, with which the valve is controlled, especially a signal for setting the position of the valve. The exhaust gas feed back is then taken into consideration in the determination of the mass of fuel to be injected.
The internal combustion engine is preferably operated with an air/fuel ratio, Lambda, equal to one. However operating states always occur in which the air/fuel ratio, Lambda, deviates from one.